EP 0118156 B1 19861015 - CIRCUIT RECOVERING THE CARRIER OF A SIGNAL MODULATED BY AMPLITUDE STEPS AND PHASE STEPS
Title (en)
CIRCUIT RECOVERING THE CARRIER OF A SIGNAL MODULATED BY AMPLITUDE STEPS AND PHASE STEPS
Publication
Application
Priority
FR 8303688 A 19830307
Abstract (en)
[origin: US4587498A] A circuit for recovering the carrier of an amplitude-and-phase-modulated input signal (in particular QAM signal) is provided with a frequency-controlled oscillator for producing the carrier, with a quadrature detector for supplying signals representing the amplitude of the input signal projected on two quadrature components P and Q of the carrier signal produced by the oscillator and for thus determining the modulation states of the input signal, and with correction means for forming a correction signal for the frequency control of the oscillator on the basis of output signals from a circuit which determines zones in the plane of the quadrature components P and Q. To provide for a satisfactory operation also in the presence of selective fading, the correction means comprises a weighting circuit connected to the zone-determining circuit for producing the correction signal in accordance with distinct weights allocated to the respective zones defined by the zone-determining circuit.
IPC 1-7
IPC 8 full level
H04L 27/34 (2006.01); H04L 27/38 (2006.01)
CPC (source: EP US)
H04L 27/3818 (2013.01 - EP US)
Designated contracting state (EPC)
BE CH DE FR GB IT LI NL SE
DOCDB simple family (publication)
EP 0118156 A1 19840912; EP 0118156 B1 19861015; AU 2530184 A 19840913; AU 558495 B2 19870129; CA 1208712 A 19860729; DE 3461013 D1 19861120; FI 82165 B 19900928; FI 82165 C 19910110; FI 840842 A0 19840302; FI 840842 A 19840908; FR 2542536 A1 19840914; FR 2542536 B1 19850712; JP H0422380 B2 19920416; JP S59168750 A 19840922; NO 840819 L 19840910; US 4587498 A 19860506
DOCDB simple family (application)
EP 84200288 A 19840301; AU 2530184 A 19840306; CA 448668 A 19840301; DE 3461013 T 19840301; FI 840842 A 19840302; FR 8303688 A 19830307; JP 4223084 A 19840307; NO 840819 A 19840305; US 58708984 A 19840307